get variable value and insert it on the code

I have this

layer.scroll\_ftec:insert(layer.myimage) 

Now I would like that myimage get the value of a variable named myvar

 

then I write for example

local myvar = "flog" layer.scroll\_ftec:insert(layer.myvar) 

How can I get that after (layer.

get the value of the variable named myvar   ?

On php it would be

layer.scroll_ftec:insert(layer.<?php echo $myvar; ?> ) 

On php it would be

layer.scroll_ftec:insert(layer.<?php echo $myvar; ?> )